CVE-2026-40339

Description

libgphoto2 is a camera access and control library. Versions up to and including 2.5.33 have an out-of-bounds read in `ptp_unpack_Sony_DPD()` in `camlibs/ptp2/ptp-pack.c` (line 842). The function reads the FormFlag byte via `dtoh8o(data, *poffset)` without a prior bounds check. The standard `ptp_unpack_DPD()` at lines 686–687 correctly validates `*offset + sizeof(uint8_t) > dpdlen` before this same read, but the Sony variant omits this check entirely. Commit 09f8a940b1e418b5693f5c11e3016a1ad2cea62d fixes the issue.

CVSS v3.1 Score

5.2

MEDIUM

CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:L

EPSS — Exploit Prediction

0.0001

Probability of exploitation

0.01%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-125 Out-of-bounds Read

References

Other References

https://github.com/gphoto/libgphoto2/commit/09f8a940b1e418b5693f5c11e3016a1ad2cea62d https://github.com/gphoto/libgphoto2/security/advisories/GHSA-42cm-m9hc-r7q8

Frequently Asked Questions

What is CVE-2026-40339? +

libgphoto2 is a camera access and control library. Versions up to and including 2.5.33 have an out-of-bounds read in `ptp_unpack_Sony_DPD()` in `camlibs/ptp2/ptp-pack.c` (line 842). The function reads the FormFlag byte via `dtoh8o(data, *poffset)` without a prior bounds check. The standard `ptp_unpack_DPD()` at lines 686–687 correctly validates `*offset + sizeof(uint8_t) > dpdlen` before this same read, but the Sony variant omits this check entirely. Commit 09f8a940b1e418b5693f5c11e3016a1ad2cea62d fixes the issue. It has a CVSS v3.1 base score of 5.2 (MEDIUM).

How severe is CVE-2026-40339? +

CVE-2026-40339 has a CVSS v3.1 score of 5.2 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0001, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-40339? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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